Abstract
The X-ray transient 2E 1050.8-6200 was recently detected by INTEGRAL/JEM-X (ATel #15624) and Swift/XRT (ATel #15630). We followed the target with NICER between 24 September and 1 October 2022 for a total exposure of 12 ks. The source count rate decreased from approx. 3 to
An averaged NICER spectrum in the 1-8 keV range can be fitted with an absorbed power-law with a photon index of 0.7+/-0.1 and a column density of (6.0+/-1) × 1021 cm-2 (chi-squared/d.o.f. = 433/350). The 0.5-10 keV and 3-10 keV unabsorbed fluxes are 8 × 10-12 and 6 × 10-12 erg/s/cm2, respectively. All reported uncertainties are 90% confidence limits.
INTEGRAL also covered the location of 2E 1050.8-6200 between 2022-09-30T22:20:51 and 2022-10-01T11:41:30 (revolution 2555) for 45 ks during the Galactic Plane observations (PI: A. Bazzano). The source was undetected in the JEM-X mosaics, leading to a 3 sigma upper limit of about 1 mCrab in the 3-10 keV band.
The flux measured by NICER is more than an order of magnitude below the INTEGRAL/JEM-X estimation on 16-17 of September 2022 (ATel #15624). This implies that 2E 1050.8-6200 has undergone a short-lived outburst that decayed rapidly even before the NICER snapshots.
NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA
An averaged NICER spectrum in the 1-8 keV range can be fitted with an absorbed power-law with a photon index of 0.7+/-0.1 and a column density of (6.0+/-1) × 1021 cm-2 (chi-squared/d.o.f. = 433/350). The 0.5-10 keV and 3-10 keV unabsorbed fluxes are 8 × 10-12 and 6 × 10-12 erg/s/cm2, respectively. All reported uncertainties are 90% confidence limits.
INTEGRAL also covered the location of 2E 1050.8-6200 between 2022-09-30T22:20:51 and 2022-10-01T11:41:30 (revolution 2555) for 45 ks during the Galactic Plane observations (PI: A. Bazzano). The source was undetected in the JEM-X mosaics, leading to a 3 sigma upper limit of about 1 mCrab in the 3-10 keV band.
The flux measured by NICER is more than an order of magnitude below the INTEGRAL/JEM-X estimation on 16-17 of September 2022 (ATel #15624). This implies that 2E 1050.8-6200 has undergone a short-lived outburst that decayed rapidly even before the NICER snapshots.
NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA
| Original language | English |
|---|---|
| Publication date | 6 Oct 2022 |
| Publication status | Published - 6 Oct 2022 |
| Series | The Astronomer's telegram |
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| Number | ATel #15645 |
Keywords
- X-ray
- Transient